The present invention relates to a cap for closing the mouth of a filler neck, and in particular, to fuel caps for closing the filler neck of a vehicle fuel tank. More particularly, the present invention relates to a cap including an attachment mechanism for enabling a user to attach the cap to the filler neck quickly and easily and establish a sealed connection between the cap and the filler neck.
Conventional fuel caps for closing the filler neck of a vehicle fuel tank typically include a closure member for closing the mouth of the filler neck and a handle for turning the closure member to mount the closure member in the filler neck. Partial-turn cam-on caps and multiple-turn threaded caps are well-known types of caps for use in closing filler necks. Although such caps are currently in widespread use, it would be desirable to provide an alternative cap that is simpler to install on and remove from a filler neck.
It is known to provide a cam-on cap of the type having a shank portion which extends into the filler neck and is provided with pairs of conventional circumferentially spaced-apart cam lugs as disclosed in U.S. Pat. No. 4,887,733, to Harris. These cam lugs operate in the customary way to engage a filler neck configured to receive a cam-on cap and retain the cap in a fully tightened position closing the open mouth of the filler neck.
Alternatively, a conventional multiple-turn cap includes a closure member that is threaded to be screwed into a threaded filler neck. For example, U.S. Pat. No. 3,820,680, to Friend discloses a multiple-turn threaded cap and a compatible threaded filler neck. Typically, a multiple-turn threaded cap must be turned at least two and one-half or three full revolutions by the user after it is inserted into the threaded filler neck to connect the cap to the filler neck and establish a liquid and vapor seal between the cap and the filler neck.
More and more vehicle drivers are using the self-service bays at gasoline stations and filling their own fuel tanks. Some people have found that it is difficult to remove and install a conventional filler neck cap during refueling. A cap that is readily installable on and removable from a filler neck by a user without a lot of effort and that is configured to establish a sturdy sealed connection between the cap and the filler neck consistently during use would be a welcomed improvement over conventional caps.
One problem with many conventional filler neck caps is that, because the handle is directly connected to the filler neck closure means, any unintentional movement of the handle in the cap-removal direction will break the seal between the closure means and the filler neck. Once the seal between the closure means and the filler neck is broken, it is possible for fuel or fuel vapor to escape from the filler neck. In some instances, such as during a vehicle accident, a release of fuel or fuel vapor can potentially create a hazardous condition.
It is known to provide a filler neck cap having a lost-motion driving connection between the handle and the closure means. See, for example, U.S. Pat. No. 4,765,505, to Harris and U.S. application No. 08/138,397, to Harris, filed on Oct. 18, 1993. These caps are designed to allow the cap handle to rotate freely relative to the closure means in both the cap-installation direction and the cap-removal direction. In some cases, a user might be inconvenienced by a cap that provides a lost-motion driving connection during cap installation as well as during cap removal. What is needed is a quick-on cap that is automatically set to have a direct-drive driving connection between the handle and closure means during cap installation and to have a lost-motion driving connection between the handle and closure means during cap removal. Such a cap would be easy to install yet incorporate a lost-motion feature that functions to prevent loss of cap seal if the cap handle is rotated inadvertently in a cap-removal direction during vehicle impact or during stress relief of vehicle components.
According to the present invention, a quick-on cap is provided for engaging a filler neck. The cap includes closure means for engaging a filler neck and handle means for rotating the closure means relative to the filler neck in either a cap-installation direction toward the filler neck to install the cap on the filler neck or a cap-removal direction away from the filler neck to remove the cap from the filler neck.
The quick-on cap also includes control means for initially providing a lost-motion driving connection during cap removal and always providing a direct-drive driving connection during cap installation. The lost-motion driving connection is established temporarily between the handle means and the closure means during initial rotation of the handle means about an axis of rotation relative to the filler neck in a cap-removal direction. The direct-drive driving connection is always established between the handle means and the closure means during rotation of the handle means about the axis of rotation in a cap-installation direction.
In preferred embodiments, the quick-on cap is a fuel cap and the filler neck is connected to a vehicle fuel tank. The control means includes a torsion spring mounted inside the cap and coupled to the closure means and the handle means. The control means also includes a drive lug coupled to the handle means and a driven lug coupled to the closure means. The torsion spring includes a top finger coupled to a top spring mount provided on the underside of the handle means, a bottom finger coupled to a bottom spring mount provided on the top side of the closure means, and a coiled portion interconnecting the top and bottom fingers. The torsion spring has a central axis and is oriented preferably to lie between the handle means and the underlying closure means so that its central axis is aligned in parallel relation to the axis of rotation of the handle means. It will be understood that the control means feature and/or the torsion spring feature could be applied to a threaded cap or a cam-on cap or other suitable closure mechanism.
During cap installation, the user always turns the closure means in the filler neck in a cap-installation or cap-advancing direction directly by turning the handle means about its axis of rotation. The cap is called a "quick-on" cap because a user need only turn the handle one-twelfth of a turn (30.degree.) in a clockwise direction once the cap is inserted into the filler neck to anchor the cap in a sealed filler neck-closing position.
Each time the quick-on cap is removed from a filler neck, it instantly and automatically "resets" itself so that a direct-drive driving connection between the handle means and the closure means is established to facilitate reinstallation of the quick-on cap on the filler neck. This reset function is achieved by automatic operation of the torsion spring to rotate the closure means relative to the handle means.
Upon removal of the cap from a filler neck, while the user is still gripping the cap by holding onto the handle means, the torsion spring inside the cap functions to rotate the closure means about the axis of rotation relative to the handle means until the drive lug on the handle means engages the driven lug on the closure means. This lug-to-lug engagement establishes a direct-drive driving connection between the handle means and the closure means for use during cap installation. In other words, the torsion spring applies a spring force which biases the driven lug against the drive lug to establish a direct-drive driving connection automatically before and during each cap installation. One benefit to the user of such a direct-drive feature is that any rotation of the cap handle in a cap-advancing direction by the user during cap installation will cause the cap closure means to turn in the filler neck so that the user can positively and quickly install the quick-on cap in the filler neck without any "lost motion" between the handle means and the closure means.
Advantageously, the torsion spring provides a direct-drive driving connection before and during cap installation without disrupting a lost-motion driving connection that is established between the handle means and closure means during an initial stage of cap removal. A sealing ring is mounted on the closure means and trapped between the closure means and the filler neck upon rotation of the closure means to its tightened filler neck-closing position. When the handle means is initially rotated by a user in a counterclockwise cap-removal direction, the handle means is permitted to rotate through a predetermined "lost motion" angle, e.g., 60.degree., relative to the closure means before establishing a direct-drive driving connection therewith to delay breaking a seal between the closure means and the filler neck. Once the direct-drive driving connection is established, further counterclockwise rotation of the handle means will cause the closure means to rotate in the filler neck from its sealed filler neck-closing position to an unsealed position. This "lost motion" feature advantageously aids in increasing the crashworthiness of the quick-on cap by lessening the likelihood that the cap will loosen an amount sufficient to break the seal during an accidental impact.
During cap removal, the user begins to turn the handle means in a counterclockwise direction relative to the filler neck against the biasing force generated by the torsion spring. Even though the user is turning the spring-loaded handle means about its axis of rotation, the closure means remains fixed in its sealed filler neck-closing position due to the lost-motion driving connection between the handle means and the closure means. Once the handle means is rotated in a cap-removal direction through a predetermined lost motion angle, e.g., 60.degree., the drive lug on the underside of the handle means is moved into engagement with the driven lug on the top side of the closure means. From this point on, a direct-drive driving connection is established and continued rotation of the handle means in a cap-removal direction causes rotation of the closure means relative to the filler neck in a cap-removal direction until the seal between the closure means and the filler neck is broken and later the cap is finally separated from the filler neck. It is only necessary to rotate the handle means another one-twelfth of a turn, e.g., 30.degree., in the counterclockwise cap-removal direction to disengage the closure means from the filler neck so that the cap can be removed to permit vehicle refueling.
Advantageously, the torsion spring functions to rotate the closure means relative to the handle means automatically after removal of the cap from the filler neck so that a lost-motion driving connection is not present and apparent to a user during installation of the cap in the filler neck. Thus, a direct-drive driving connection between the handle means and closure means is automatically established during cap installation without disabling a lost-motion driving connection that is always established between the handle means and closure means during an initial stage of cap removal.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.